How to relubricate/service a troublesome or noisy fan.

[KLiKzg]

I'm a lazy bum; open up the cap, add engine oil and hope for the best

Which engine oil?

Anyhow...some grease or oil is great, after failure. As long as it is running, do not mess with it.
Once it failed, probably the grease or oil is cooked. So anything you add, must be: isolation & greasy/oily.

 

[Shrek]

Mobil 1 5W-30

I beg to differ, I think it important to catch things before it stops running, to avoid damage.

I have opened up most all of my room fans to oil them, long before they stopped turning. One trick I try is to rotate the outer cage and if the fan blades follow the motion, the bearings are probably in need of oil.

 

[freeagent]

If the magic juice leaked out, and the relubrication ended up only being a short term fix, then chances are the tolerances have worn, and the unit is done.

 

[KLiKzg]

Mobile 1 5W-30

I beg to differ, I think it important to catch things before it stops running, to avoid damage.

I have opened up most all of my room fans to oil them, long before they stopped turning. One trick I try is to rotate the outer cage and if the fan blades follow the motion, the bearings are probably in need of oil.

Well, even 5W-30 is too thick for the fan application...I would rather go with 0W-20. But what do I know, as a mech.eng.?

If fans stop running, then you have programs to stop the calcs...like for BOINC or some mining.

So I do not change anything until there is rattle or sound, when rotating. But I also gave up from normal cars, using more noisier blower cards, which do not increas temp. in case.

 

[Shrek]

Tribology was never really my thing.

 

[KLiKzg]

I am more concerned about "too thick oil", which will lower the rpms on 3~15W engine.

 

[Bill_Bright]

If the magic juice leaked out, and the relubrication ended up only being a short term fix, then chances are the tolerances have worn, and the unit is done.

Well, at the very least, damage that cannot be repaired has been done and further degradation is inevitable from there. The bearings are no longer perfectly round or smooth. Same with the bearing channels. As freeagent noted, the excessive wear will adversely affect tolerances. There will be "slop" in the motor. Re-lubing may slow further damage but not stop it. So regardless, re-lubing is just a temporary solution. How long it will last is anyone's guess. It could be years or days before that "slop" potentially causes the bearings to seize and the motor stop spinning.

IDK. I am not one who likes to waste money but IMO, the cost of a brand new replacement fan is dirt cheap compared to the hardware and data it protects. So when a fan starts to rumble, I simply replace it and be done with it.

I think it important to note this thread is about low voltage DC computer case and CPU fans. Not big AC blower motors like those found in HVAC systems or desk/room fans. Big difference.